Measurements of soil temperature for monitoring of the soil water behavior in an embankment slope during periodic rainfall
Abstract
One of the most common causes of slope disaster (e.g. landslide, slope failure and debris flow) is heavy rainfall. Distributions of soil moisture and soil suction stress are changed by rain water infiltration. Monitoring of soil water behavior is crucial for prediction of the slope disaster. This study focuses on soil temperatures of a slope as a detector for monitoring soil water behavior. Soil temperature is varied by soil water condition, this is, infiltrating water transports thermal energy downward and thermal property of soil is shifted by containing of soil water. The purpose of this study is to detect the changes in soil water behavior caused by infiltration of rainfalls using measurement of soil temperature. For this purpose, we had carried out the measurements of soil temperature during various rainfalls (Yoshioka et al., 2013). In addition, we measured soil temperature and soil water content at several depths in a slope of an experimental embankment during various intensities of periodic and/or continuous rainfalls. In this presentation, we represent the details of the experiments and the results. Experiments were performed using the experimental embankment at NIED in Japan, which is about 7.3 meters tall and 27 meters wide. The embankment is located in a large-scale rainfall simulator. This facility is about 73 meters long, 48 meters wide and 20 meters tall. We measured soil temperature and volumetric water contents in the slope of the embankment, meteorological condition and rain water temperature. The rainfall intensities were 30, 60, 90 and 120 mm/h. The artificial rainfalls were carried out 10th, 17th, 24th, 31st, May and 10th, 11th, 12th June, 2013. As the results, soil temperature at many points in all experimental days rose caused by rainfalls, but the temperature at some points didn't change. We had two forms of soil temperature changes; one was a steep rise and the other was a gradual rise. In the case of periodic rainfall, soil temperature at some points changed in each rainfall. The soil temperature rose greater in the rainfall with higher intensity than that in the rainfall with lower intensity. The soil temperature change has similar tendency as the volumetric water content change. Both soil temperature and volumetric water contents rose after the start of rainfalls and decreased gradually after the finish of them. These results indicated that the soil temperature change reflected the soil water behavior even when periodic rainfall occurred. Reference: Yoshioka et al. (2013) Measurement of soil temperature in the slope of an embankment using a large-scale rainfall simulator, Proceedings of the 11th SEGJ International Symposium (submitted)
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMNH23A1523Y
- Keywords:
-
- 4300 NATURAL HAZARDS;
- 1800 HYDROLOGY;
- 1810 HYDROLOGY Debris flow and landslides;
- 4303 NATURAL HAZARDS Hydrological